1. Field of the Invention
The present invention relates to an apparatus used in testing the electrical characteristic of semiconductor devices.
2. Description of the Related Art
FIG. 3 shows appearance of three typical semiconductor devices (hereinafter also referred to simply as "device") 1 each equipped with external output terminals 1a, 1b and 1c, respectively.
FIG. 28 schematically shows a conventional testing apparatus for testing a semiconductor device (referred to as a semiconductor testing apparatus). As seen from FIG. 28, the testing apparatus includes a tester body 110, four test heads 111 and four test handlers 116 are shown. Each test handler 116 integrally includes a handler body 113, a loader 114 and an unloader 115. The test head 111 is attached to the handler body 116. The test head 111 incorporates a contact (not shown) in contact with the above device 1 and electrically connected through a cable 112 to a tester body 112 for testing the electric characteristic of the device. The handler body 113 serves to transport the device 1. The loader 114, which is adjacent to the handler body 113, supplies a pallet containing the device 1 before test to the handler body 115. The unloader 114, which is also adjacent to the handler body 113 and arranged on the side opposite to the loader 114, receives the pallet containing the device 1 after test unloaded from the handler body 113.
An explanation will be given of the operation of the semiconductor testing apparatus. When the pallet containing the device before test is cast into the loader 114, it is supplied into the handler body 113 therefrom. The device 1 supplied into the handler body 113 and housed in the pallet is pushed up so that the external output terminal and the contact housed in the test head 111 are brought into contact with each other. In this state, the tester body 110 tests the device with respect to its various electric items. Upon completion of the test, the device 1 is housed in the pallet, discharged from the handler body 113 and housed in the unloader 15.
Because of the structure described above, the above conventional semiconductor testing apparatus has the following defects. An large installing area is needed because of the test handler 116 provided for the test head 111 connected to the tester body 110. In addition, since the test handler 116 necessarily requires the loader 114 for supplying the pallet containing the device before test into the handler body 113, the unloader 115 for housing the device 1 after test discharged from the handler body 113 and a controller therefor, the semiconductor testing apparatus is very expensive.
Further, since the tester body 110 is expensive, its availability factor must be enhanced. This required the time and effort of equally arranging the pallets each containing the device and also casting the pallet into the test handler 116 so that the operation of each of the test handlers 116 terminates at substantially the same timing. Further, the test handlers 116, which are individual from each other, require the individual supply/discharge of the pallet and their running. This results in poor test efficiency.